of British Mollusca. 
75 
Genus 5. Ancula, Loven. 
92. Ancula cristata (Alder). 
Shetland (A. M. N .), Moray Firth (Gordon), St. Andrews 
(M c In tosh), Plymouth (Garstang ) . 
Taken abundantly at Hilbre Island, Cheshire, by Prof. 
Herdman, who found one specimen u entirely of a hyaline 
transparent white colour, without any yellow markings on 
the dorsal papillae, and with no opaque white pigment on any 
part of the body.” Arran, N.B., and Firth of Forth ( Herd- 
man ) . 
Distribution . Boulogne (B ouch.- Chant.) , Denmark ( Kroger ') , 
W. Norway (G. 0. Sars ), Kiel (Meyer cfe Mobius ), Heligo- 
land (Frey & Leuckart ), Iceland ( Morch ), Sweden (Loven). 
Genus 6. Thecacera, Fleming. 
93. Thecacera pennigera (Montagu). 
Off Lowestoft, 16 fath. (Meyer), 20 fatli. off Rame Head, 
Plymouth (Garstang). 
Distribution. Sicily ( Quatrefages ), N. and N.W. France 
(Fischer) . 
94. Thecacera virescens, Aid. & Hanc. 
95. Thecacera capitata, Aid. & Hanc. 
Genus 7. Crimora, Aid. & Hanc. 
96. Crimora papillata , Aid. & Hanc. 
The only two known specimens of this Nudibranch are 
those which I took at Guernsey, the one in 1858 the other in 
1865. They occurred in shallow water. 
Genus 8. Polycera, Cuvier. 
97. Polycera quadrilineata (Muller). 
Shetland and Cumbrae (A. M. N.) ; St. Andrews (McIn- 
tosh), Plymouth (Garstang), Moray Firth (Gordon), Firth of 
Forth (McBain). 
Distribution. Mediterranean (Marion &c .), Adriatic (Bergh 
c be.), Kiel ( Meyer & Mobius), Denmark (Kroger die.), 
Western France (Fischer), Sweden (Loven), S. and W. Nor- 
way (G. 0. Sars), Heligoland, 5-6 fath. (Meyer-). 
Synonyms. Doris cornu ta, Abildgaard, D. flava, Montagu, 
